Spells are a specific type of power. For each power slot, you can instead elect to take two spells. With a high MAG score, you may gain extra spells per power slot, but the default is two.
Spells are indicated on power lists by putting their names in
italic.
A character may cast three spells per thread, with an extra spell for every three points in STA. They further gain an extra spellcast per thread with every level. In mathematics, your character's spellcast = 3 + level + (STA/3).
You create your own spells. Spells can have virtually any effect. You may base them on
D&D spells or other tabletop sorcery rules, but it is better to underpower your spells than to overpower them when converting them for ARCANA. If in practice, your spell is over or underpowered, we can tweak balance as we play.
You may utilize stats when writing spells. A generic heal or attack spell typically does your character's MAG score worth of damage or healing. A spell that hits multiple targets will probably do half MAG for damage, or perhaps it will cost you 1 STA to cast. A spell that deals damage and issues a debuff will likely do half MAG damage, and the debuff would not be so severe as a spell that is purely debuff and no damage.
Offensive spells can generally be avoided with AGI and deals damage to STA. With specific spells, it may be more logical to target stats besides AGI; make a note of this in your spell write-up in your powers post. For example, instead of using AGI to dodge a sleep spell, perhaps you resist it with STA or MAG instead. Your sleep spell may target STA, another person's sleep spell may target MAG--it depends on your choice of flavor.
Blood magic is a thing; you may justify a spell being more powerful than average by taxing your own STA. You may also make a stronger spell cost multiple spellcasts. However, bear in mind that with the immense potential of a dedicated mage, we'd prefer that you underpowered your spells rather than seek to create a godmodding Badass McGee.
Besides for spells, there are also
spell-like effects. In short, if your character were in an anime, a spell-like effect is any sort of special move that they'd yell out a poetic attack name for before using. That's a spell-like effect; it's a particularly potent skill that deals damage in a way that scales like a spell. It may not necessarily be an attack. A ninja type character could take
smoke bomb and
hide in plain sight as spell-like effects. An ancient bloodline that practices meditation may know secret techniques for increasing STA or POW as a buff.
The distinction between powers and spell-like effects is that powers are unlimited in use, but they are not typically damage multipliers. Without spell-like effects, a hit with a sword deals 1 STA damage by default, possibly improved slightly by powers (ex powers: Enchanted Weapon, Bloodrage). A combat power like bloodrage may increase all damage dealt by +1 and reduce all damage taken by -1 as an overall bonus when in bloodrage. A spell-like effect, however, may deal your POW in damage, or perhaps half that with potential ride-on effects, in one post.
Spell-like effects are gained exactly as spells are. They are bought at two per power, more if your character has a high MAG score. They may utilize a spell-like effect three times per thread plus 1 for every 3 points in STA. They can an additional cast per level.